As the present society ages, it is anticipated that there will be an increase in degenerative and dysfunctional spinal disk conditions. Pain associated with such disk conditions can be relieved by medication and/or surgery.
Over the years, a variety of intervertebral implants have been developed in an effort to relieve the pain associated with such degenerative and dysfunctional disk conditions. For example, U.S. Pat. No. 4,349,921 to Kuntz discloses an intervertebral disk prosthesis. The Kuntz prosthesis is designed to restore the space between the disks.
U.S. Pat. No. 4,714,469 to Kenna discloses a spinal implant that fuses vertebrae to the implant. The implant has a rigid body that fits between the vertebrae with a protuberance extending from a vertebral contacting surface and into the vertebral body.
U.S. Pat. No. 5,258,031 to Salib et al. discloses another prosthetic disk with a ball that fits into a socket.
U.S. Pat. Nos. 5,425,773 and 5,562,738 are related patents to Boyd et al. that disclose a disk arthroplasty device for replacement of the spinal disk. A ball-and-socket are provided to enable rotation.
U.S. Pat. No. 5,534,029 to Shima discloses an articulated vertebral body spacer with a pair of upper and lower joint pieces inserted between the vertebrae. An intermediate layer is provided to allow for movement between the upper joint piece and the lower joint piece.
U.S. Pat. No. 5,782,832 to Larsen et al. discloses a two-piece ball-and-socket spinal implant with upper and lower plates for insertion within the intervertebral space.
U.S. Pat. No. 6,156,067 to Bryan et al. discloses a prosthesis having two plates with a nucleus therebetween.
None of these solutions provide an implant that restores a wide range of natural movement.
Accordingly, what is needed is an implant for alleviating such conditions and that restores natural movement.